Fluid cooled enclosure providing access ports



G. J. scHoEssow 2,704,999

FLUID coouan ENCLOSURE PROVIDING ACCESS PORTS 2 Sheets-Sheet l N$ N gINVENTOR G/ezz J Jc/zoessow i M a mm mm w L NMW m m m L w W m A \i N mKN \I w m b wm OM [I'll m m 3 RL m mi 0mm I m I '1 a M M m Q R c w ||||1a Q (L March 29, 1955 Filed July 8, 1948 ATTORNEY March 29, 1955 G. J.SCHOESSOW 2,704,999

FLUID COOLED ENCLOSURE PROVIDING ACCESS PORTS Filed July 8, 1948 2Sheets-Sheet 2 INVENTOR ATTORNEY United States Patent Ofiice 2,704,999Patented Mar. 29, 1955 FLUID COOLED ENCLOSURE PROVIDING ACCESS PORTSGlen J. Schoessow, Barber-ton, Ohio, assignor to The Babcock & WilcoxCompany, New York, N. Y., a corporation of New Jersey Application July8, 1948, Serial No. 37,642

7 Claims. (Cl. 122-65) The present invention relates in general to afluid cooled enclosure providing ports through which interior chamberconditions may be observed and interior wall surfaces renderedaccessible for inspection and cleaning.

ln boiler construction, for example, wherein the outer enclosing wallsare generally upright and rectangularly arranged, it has been customaryto provide wall ports or openings in the planar side or end wall areasfor the purpose of observing interior furnace conditions, or forremoving slag accumulations from the various interior surfaces by meansof a lance or other implement inserted through the opening. Each portis, of course, fitted with a suitable closure means and, when providedin a planar wall area, generally results in an assembly whichappreciably limits the angle of vision and also the available workingrange through any one port. It has therefore been necessary to provide aconsiderable number of such ports in each of the surrounding walls inorder to permit observation of the chamber throughout at least thegreater part of its cross section, and to render interior wall surfacesaccessible for observation and cleaning through the various ports. Incertain boiler constructions, the formation of ports in planar wallareas is often dependent on the design and support of the unit whichmight require their relocation in less advantageous positions.

An important feature of my invention relates to the formation of aninspection port or access opening at the corner formed between twointersecting walls whereby the angle of vision is substantiallyincreased and conditions within the chamber may be observed throughoutits entire cross section. Similarly, the available working range isincreased and lancing of adjoining wall areas may be readilyaccomplished. This is particularly desirable in heat exchange apparatushaving fluid cooled walls defining a combustion chamber in view of thenecessity of maintaining the exposed inner wall surfaces clear of excessslag accumulations for increased efficiency of heat transfer.

Another object of my invention relates to the formation of an inspectionand lance port between wall tubes normally in contact or otherwiseaffording a width of intertube space less than the width of access.opening required.

An additional object relates to the formation of an access openingbetween closely spaced tubes associated with adjoining walls, and toprovide a suitable closure means for such an opening.

A further object of my invention relates to the support of a wall portclosure means on tubes associated with adjoining wall areas, and to themaintenance of such tubes in relatively fixed relation adjacent thesides of the port whereby the closure means may be rigidly attached tothe tubes without risk of damage to its component ports.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described a preferred embodimentof my invention.

Of the drawings:

Fig. 1 is an exterior front elevational view of a boiler unit embodyinga fluid cooled enclosure constructed in accordance with my invention;

Fig. 2 is a plan view of the unit shown in Fig. 1, partly in sectionalong line 22;

Fig. 3 is a fragmentary exterior elevational view of Fig. l, rotatedthrough 45, showing the formation of a corner port and indicating theclosure means therefor;

Fig. 4 1s, a sectional plan view, taken along line 4-4 of Fig. 3 showingfurther details of the corner construction;

l igc.1 5 is a side view of the structure shown in Fig. 3; an

Fig. 6 is a fragmentary sectional plan view of Fig. 1, taken along line6-6, for example, directly above one of the wall-supporting buckstayunits, with the outer casing omitted.

in more detail, Figs. 1 and 2 illustrate an embodiment of my inventionin a known type of vapor generating unit 10 having a setting ofsubstantially horizontal cross section as defined by upright front andrear walls 12 and 13, respectively, together with oppositely disposedupright side walls 14 and 15. The space within the setting includes acombustion chamber or space 17 lying at one side of an upright fluidcooled wall, herein indicated by dotted line 18, by which the combustionchamber is partitioned from a boiler tube space 19 at the opposite side.One or more burners 21 of a type suitable for the fuel to be burned areinstalled in the front furnace wall 12, for example, to provide a sourceof heating gases. Air for combustion is delivered to the burners bymeans including a wind box 23 and an air supply duct 24.

The partition wall 18 terminates short of the rear furnace wall 13 toprovide a passage 25 through which heating gases are discharged fromcombustion chamber 17. The gases entering the tube space 19 are causedto flow horizontally, across a bank of boiler tubes 26 in a plurality ofpasses defined by cross baflies 27 and 28, and are finally dischargedthrough gas outlet 29.

In this form of boiler unit, all walls surrounding the combustionchamber are fluid cooled as provided, for example, by tubes 2, 3, and 5,in exterior upright walls 12, 13, and 15, respectively, and also bytubes 8 in the interior upright partition wall 18. The lateral boundaryof the chamber is completed by tubes 30 which are arranged in one ormore rows across the gas flow passage 25 to provide a screen in advanceof tubular heating surface in tube space 19.

It may be assumed, 'without requiring specific illustration, that theentire weight of the unit including walls 12, 13, 14, and 15 istop-supported, with the weight transferred to the customary structuralframework. It is to be understood however that in certain instances,depending on the particular arrangement of parts, for example, a unit ofthis general type may desirably derive its vertical support from below,as disclosed in my copending patent application Serial No. 654,239,filed March 14, 1946, now Patent No. 2,583,599. In either case, thevertical support of all walls is made from a common elevation along thevarious Wall tube lengths, whereby the tubes in each two adjoining wallsmove in unison in response to expansion and contraction so as to obviaterelative vertical movement of one wall with respect to another,particularly at the corners of the setting.

In addition to the customary vertical support provided for each uprightwall of the unit from a predetermined elevation, it will be noted thatthe walls 12, 13, 14, and 15 are afforded lateral support at severalelevations by means of horizontally extending buckstay units 31, 32, and34, each of which is constructed substantially as shown for similarunits in the aforesaid copending application. Accordingly, one buckstayunit, namely unit 31, encompasses all four upright walls of boiler unit10, while a second buckstay unit 32, associated only with Walls 12, 13,and 15, is secured at its inner end to the lower boiler drum 35. Anadditional unit 34, which may be tied-in to the structure of wind box23, is associated with the four upright walls 12, 13, 15, and 36 whichdefine the lower extended portion of combustion chamber 17, atelevations below muddrum 35, the buckstay unit 34 being locatedpreferably below burner level and above the converging hopper portion37.

As indicated in Fig. l, inspection doors 38 are desirably arranged atdifferent elevations, and at each elevation, preferably at an outercorner of combustion chamber 17 from which location a view of the entirecross section of the chamber may be had through a single port 39 whenthe door is open. However, in order that all portions of the chamber maybe viewed at reasonably close range, and from different directions, andthe cleaning of the various wall surfaces facilitated, the ports 39 arepreferably formed at both outer corners of chamber 17, as indicated inFig. 2. For a unit of the type shown, it will be understood that, exceptfor a region including a port 39, the wall tubes 2, 3, and are arrangedvertically and in parallel relationship throughout the major portions oftheir lengths and are closely spaced in their respective rows adjacentthe inner face of the heat insulating refractory material 40.

The ports 39 and doors 38 are thus associated with corners which aredefined by walls in which the tubes are closely spaced, and sincesimilar close spacing of tubes is maintained across each outer corner,there is normally no intertube space provided of a width correspondingto the width of inspection or lance port required. In side wall 15, forexample, which is the common defining wall for both outer corners, thetubes 5, with the exception of the terminal tubes 5a at opposite ends,are arranged at center-to-center spacings equal to the tube diameters soas to place successive tubes in contact substantially throughout therow. As will be noted from Fig. 6, each end tube 5a is displaced at anangle of approximately 26 /2 from the planar arrangement of theremaining tubes 5 of the row so as to occupy a position midway between,and in planar alignment with, a next to the last tube 5b of the tube row5 and an end tube 2a or 3a of the rows of tubes associated respectivelywith front wall 12 and rear wall 13. The end tubes 2a, 2b and 5a, 5b ofthe respective rows in adjoining walls 12 and thus constitute a seriesof upright wall tubes arranged in closely spaced succession across thefront outer corner of chamber 17, while the end tubes 3a, 3b and 5a, 5bof the respective rows in adjoining walls 13 and 15 constitute a similarseries of upright wall tubes arranged in closely spaced successionacross the rear outer corner of chamber 17.

Fig. 6 also illustrates the arrangement of buckstay unit 32 at andadjacent outer corners of the combustion chamber as formed between sidewall 15 and the front and rear walls 12 and 13. Buckstay units 31 and 34at other elevations are of the same general arrangement,

and in each case, unit 31, 32, or 34 may be considered as being ofessentially the same construction as a simi' larly positioned buckstayunit disclosed in said prior application. Each buckstay unit thereforeincludes a tie bar 41 in each of the front and rear walls 12 and 13, anda tie bar 42 in side wall 15, with the tie bars secured to tubes 2, 3and 5 in their respective rows, and meeting at the corners 43 where theyare rigidly con nected, as by welding. Buckstays 45 and 46 for therespective walls are secured at intervals therealong to thecorresponding tie bars by tie plates 47 and 48 and, for adjoining walls,are interconnected at each outer corner by a horizontally disposedgusset plate 49 welded to the adjacent tie bars 41 and 43. Slotted boltholes are provided in the tie plates and gusset plates to permitlongitudinal movement of each tube-lined wall 12, 13, or 15 relative tothe corresponding buckstay, as more fully described in the aforesaidprior application.

As indicated in Fig. 4, each row of wall tubes terminates in spacedrelation to the inner surface of the adjoining wall, at right anglesthereto. Accordingly, the end tube 2a in wall 12 is spaced at a distanceof one tube diameter from the inner surface of wall 15, and the end tube5a in wall 15 is spaced at a distance of one tube diameter from theinner surface of wall 12. Thus, a plane tangent to the transverselyaligned tubes 5 at one side is also tangent to the end tube 2a at theopposite side of the plane. Similarly, the end tube 511 in wall 15, andthe transversely aligned tubes 2, in wall 12, are disposed at oppositesides of a common tangential plane parallel to wall 12. It will be notedthat in wall 15, the end tube 5a is arranged at the samecenter-to-center spacing from the next adjacent tube 5b as fortransversely aligned tubes 5 of the row, and that its displacement fromthe centerline of the row is one-half of its diameter,

thereby placing the centerline of tube 5a in the first above mentionedcommon tangential plane, parallel to wall 15.

With wall tubes arranged as described, a corner port 39 may be formed bylocally displacing intermediate portions of one or more tubes of each ofthe adjoining walls, at and adjacent the desired port location, therebyrepositioning certain tube portions so as to define a port ofpredetermined width, and other tube portions so as to provide suitablesupport for the port closure means as hereinafter explained. In theillustrative embodiment, the local displacement of intermediate tubeportions is effected by reverse bends which are formed to radiiconsiderably greater than the tube diameters and which serve to restorethe various tube length portions to their normal positions at elevationsabove and below the port. As indicated in Figs. 3, 4, and 5, for wall12, the end tube 2a, and the next adjacent tube 2b, are reversely bentin planes at right angles to each other, thereby displacing a portion ofthe tube 2b to the position 2b outwardly of its original position ofplanar alignment with other tubes 2. The displacement of tube portion212 is at right angles to the plane of the row of tubes 2, and theextent of displacement, at least one tube diameter. The end tube 2a isformed with reverse bends in the plane of the row of tubes 2 and itsintermediate portion 2a moved to the space made available by thedisplacement of the tube length portion 2b. The tube length 2a is thusin axial alignment midway of its length with the undisplaced straightlength portions of the next adjacent tube 212.

The two end tubes in the adjoining wall 15 are similarly formed withreverse bends and their intermediate portions similarly displaced. Thus,in wall 15, the next to the last end tube 5b of the row is provided withan intermediate portion 5b which is displaced a distance of at least onetube diameter to a position outwardly of the row of tubes 5, with thedisplacement being eifected in a plane at right angles to the row. Theterminal tube 5:: is reversely bent in a plane inclined to the plane ofthe row of tubes 5 and containing the centerlines of tubes 5a and 511.Thus, tube 5a is provided with an intermediate portion 5a which occupiesa portion of the space made available by the displacement of the tubeportion 5b, in which position the tube portion 5a is in axial alignmentmidway of its length with straight, undisplaced portions of tube 512,and thereby in transverse alignment with the row of tubes 5.

As herein illustrated, the closure means for a wall port 39 comprises adoor 52 having a pivotal connection with a door frame 53 whereby thedoor is arranged for horizontal swinging movement about a vertical axisas provided by hinge pin 56 which extends through lugs 57 and 58 on thedoor and the frame respectively. A door-latching mechanism is providedwhich includes a pivoted latch 59 on the door, and a stationary catch 61on the frame.

The door frame 53 is formed with an inner flange 62 which defines arectangular frame opening 63 symmetrically arranged with respect to theport 39, the flange 62 having vertically disposed side portions 64 ofenlarged cross section toward their inner ends and presenting arcuatesurfaces 65 in contact with the outwardly displaced wall tube portions2b and 5b at opposite sides of the port. The frame 53 is secured to thewall by means of studs 67 having their inner ends threaded into socketmembers 68 which are welded to the tube portions 2b and 5b, and havingtheir outer ends threaded to receive clamping nuts 69. The outwardlydisplaced tube portions 2b and 5b are preferably maintained straight andvertical, parallel to undisplaced tubes of the respective rows,throughout the height of the frame opening 63, and continuing above andbelow the opening, thereby affording a wide entrance to port 39 andproviding a right cylindrical surface suitable for the assembly of doorframe 53 thereto. A rim of packing 71 surrounds the opening 63 andprovides a door seat surface 72 in a plane parallel to the straightlength tube portions 2b and 5b to which the frame is secured. The wallcasing 73 is suitably secured to marginal portions of the frame by meansof bolts 74. It will be noted that the frame flange portions 64 havetheir inner sides inclined to the plane of the door seat surface 72 atan angle suitably greater than 45 and are disposed to the outside ofconverging planes A-A which are tangent,

respectively, to the port-defining tube portions 2a and 2b, and 5a and5b, at opposite sides. The planes A-A, and the tube portions to whichthey are tangent, are arranged at right angles to each other and thusare parallel to adjoining walls at the corner so as to afford a line ofvision throughout the extent of each wall.

The door assembly 52 includes a layer of high temperature blockinsulation 75 together with door lining tile 76, suitably in twosections and extending inwardly to about the centerlines of thedoor-supporting tubular elements 2b and 5b, the tile insert 76 beingengaged by a frame-like tile retainer 78 having inwardly converging wallportions as indicated in Figs. 4 and 5, and held in position therebythrough the medium of studs 79 which are received in lugs 81 on the tileretainer and extend through the wall of the door. The tile insert 76 andthe tile retainer 78 are each formed with inclined peripheral walls, andparticularly with inwardly converging side walls 82 which conformsubstantially to the inclination of the converging tangential planesA-A. This formation of the tile insert and tile retainer permits theinstallation of a thick layer of refractory material which practicallyfills the flared entrance to the port when the door is closed, and whichobviates any restriction of the available sight or working angle whenthe door is open.

The arrangement described provides numerous features which areparticularly advantageous in the design, construction, and maintenanceof heat exchange apparatus. These advantages stern largely from thenovel arrangement of each port at a corner of the enclosed chamber,whereby one door thus located provides better and more completeobservation than has heertofore been possible with a plurality of doorsvariously positioned in planar wall areas. In the design of a vaporgenerating unit, for example, where a considerable area of the frontfurnace wall is covered by a burner box and associated air ducts, thereis often a scarcity of room for a door of adequate size in the remainingplanar area of the same wall, whereas a door may readily be positionedat the adjacent corner because of the smaller planar wall area requiredand the fact that the total required area is distributed over the cornerportions of two walls. Moreover, a door located at the corner of afurnace is' in a cooler location than a planar furnace wall area. Froman operating standpoint, it is a great improvement to provide a singlecorner port through which the entire cross section of a chamber may beobserved, instead of having to provide a plurality of ports at otherlocations for the same purpose, thereby enabling the operator to makeall required observations by opening only one door,

and as a result, increasing the operator performance and efficiency.

While in accordance with the provisions of the statutes I haveillustrated and described herein the best form of my invention now knownto me, those skilled in the art will understand that changes may be madein the form of the apparatus disclosed without departing from the spiritof the invention covered by my claims, and that certain features of myinvention may sometimes be used to advantage without a corresponding useof other features.

I claim:

1. In a fluid heater having upright walls defining a heating chamber ofhorizontal polygonal cross section, said walls having fluid heatingtubes associated therewith including a series of said tubes arrangedupright across a corner formed between two of said walls, and meansforming a port at said corner affording a view of said chambersubstantially throughout said cross section, said port having uprightside wall portions diverging outwardly from said chamber and eachportion being disposed substantially parallel to the adjoining chamberwall which is at the opposite side of said port, said side wall portionsrespectively comprising a pair of contiguously arranged interior andexterior tubes of said series each having an intermediate portionhorizontally offset in the form of a single plane bend throughout theheight of said opening, said exterior tube of said pair having itsoffset portion extending toward the outer side of said series of tubesand said interior tube of said pair having its offset portion extendingto the space vacated by the single plane bend of said exterior tube.

2. A furnace enclosure comprising upright fluid cooled walls meeting ata corner and supported from a common elevation so as to obviate movementof one wall relative to the other at said corner as a result of walltemperature variations, said walls having upright fluid heating tubesassociated therewith and comprising a series of said tubes arrangedacross said corner, means defining an opening in said furnace enclosurecomprising an exterior tube of said series at each side of said cornerand opening having an intermediate portion offset outwardly with respectto said furnace enclosure, and a pair of interior tubes of said serieseach respectively contiguous to one of said exterior tubes and having anintermediate portion oifset laterally into the space vacated by theoutwardly oifset portion of the adjacent exterior tube, tie bar meanstying together successive tubes of each of said walls including some ofsaid tubes having portions defining said opening, means rigidlyinterconnecting said tie bar means for the respective walls at saidcorner, a door frame secured to certain of said offset tube portionsdefining opposite sides of said opening, and a door for said openingmounted on said frame.

3. In a fluid heater having upright walls meeting at a corner, saidwalls having upright fluid heating tubes associated therewith includinga series of said tubes arranged in successive relationship across saidcorner, and means defining an opening at said corner of greater widththat the total intertube space afforded between tubes of said series,said means comprising a pair of contiguously arranged interior andexterior tubes of said series at one side of said opening havingintermediate portions offset respectively in intersecting planes at acommon elevation, said interior tube having its offset length portiondisposed at the intersection of said planes in axial alignment with themajor length portion of said exterior tube.

4. An enclosure comprising upright walls meeting at a corner and havingupright tubes arranged in rows extending along said walls and continuinginto said corner, and means defining an opening at said cornercomprising an intermediate tube of each of said rows having a portionoffset outwardly from its row in a plane extending transversely of itsrow, and a terminal tube of each row contiguous to said intermediatetube and having a portion offset in a plane intersecting said firstnamed plane, said offset portion of said terminal tube extending to thespgce vacated by the offset portion of said intermediate tu e. I

5. An enclosure comprising upright walls meeting at a corner and havingupright tubes arranged in rows extending along said walls and continuinginto said corner, and means defining an opening at said cornercomprising an intermediate tube of each of said rows having a portion ata common level oflset outwardly from its row in a respective uprightplane extending transversely of its row, and a terminal tube of each oneof said rows in contiguous relation to the said intermediate tube of itsrow and having a portion offset longitudinally of its row into aposition in said respective upright plane inwardly adjacent said firstnamed offset tube portion.

6. An enclosure comprising upright walls meeting at a corner and havingupright tubes arranged in rows extending along the respective walls andcontinuing into said corner, and means defining an opening at saidcorner comprising an intermediate tube of each of said rows having anintermediate portion at a common level offset outwardly from its row ina respective upright plane extending transversely of its row, and aterminal tube of each row contiguous to the respective intermediate tubeof its row and having an intermediate portion offset longitudinally ofits row into a position in said respective upright plane inwardlyadjacent said first named offset tube portion, means tying togethersuccessive tubes of said rows adjacent said corner, a door frame rigidlysecured to said outwardly offset tube portions, and a door for saidopening mounted on said frame.

7. In heat exchange apparatus having a heating chamber of horizontalpolygonal cross section, upright fluid cooled walls defining saidchamber comprising fluid heating tubes associated with said walls andincluding a series of said tubes arranged upright across a corner ofsaid chamber, and means defining an opening at said corner affording aview of said chamber substantially throughout said cross section, saidopening being formed between separate but adjacent groups of tubes ofsaid series and having upright side walls of which each side wall ofsaid opening is defined by horizontally displaced portions of thenearest and innermost pair of tubes of a separate one of said groups,said displaced tube portions at each side of said opening lying tangentto a plane ex tending parallel to the chamber wall which is at theopposite side of said opening, said plane being at a location inglardlyspaced from said chamber wall at said opposite 51 e.

323,882 Pratt Aug. 4, 1885 Lapp Sept. 17, Liptak Wells May 18, BaileyMar. 12, Lucke Nov. 26, Millar Dec. 24, Bennett Mar. 22, Jackson Oct.18, Van Brunt et al May 20, Kruger June 3, Artsay Aug. 3,

